We generalize the concept of industry, which stems from the analysis of single-product economies, to that of sector. The sector concept can be applied to economies with or without joint-product processes and pure capital goods. A sectoral economy is an economy characterized by the super-adjustment property: any strictly viable subset of methods can adapt itself to an arbitrary final demand. Given a few additional asumptions, the competitive prices are minimal in a sectoral economy, so that the subset of competitive methods is uniquely defined and the non-substitution property holds.